Nowadays, touch panels have been widely applied in displays of various electronic devices, such as smart phones, tablet computers, personal digital assistants (PDA), digital cameras, e-book readers and wearable electronic devices. According to the medium used, touch panels are usually categorized into a resistive type, a capacitive sensing type (a capacitive type), an electromagnetic induction type (an inductive type), an infrared type, a surface acoustic wave type and so on.
An existing inductive touch panel generally uses a rectangular coil to receive signals from a dedicated stylus, so as to generate electromagnetic induction signals.
However, such an inductive touch panel can only sense signals having a higher frequency, e.g., sent by the stylus. If it is touched directly by a human finger, the coil may not sense the touch signals since the finger has lower permeability. Accordingly, touch control cannot be achieved.